I used to think my problem with comic-book superhero movies was that I didn't grow up with a passion for comic books. Or superheroes. Now I realize that I needn't be defensive in front of erudite fanboys. I may have no passion for mediocre comic-book superhero movies like ''X-Men,'' which came out three summers ago -- let alone junky derivatives like the recently released ''Bulletproof Monk.'' But without ever having heard of Nightcrawler (Alan Cumming) before that tattooed, teleporting, devil-tailed, psalm-chanting, German-accented mutant made his attention-grabbing entrance in the opening scene of X2: X-Men United, I fell completely and happily under the sway of this new and improved sequel.
My erudite-fanboy colleagues at EW are delighted because the movie wastes no valuable time explaining to newcomers why Magneto (Ian McKellen) is locked up in a plastic prison, or why the return of the broody, adamantium-clawed rebel without a cause, Wolverine (Hugh Jackman), is such a big deal to telekinetic Jean Grey (Famke Janssen), weather-manipulating Storm (Halle Berry), life-sucking Rogue (Anna Paquin), wizardly Professor Charles Xavier (Patrick Stewart), and the students at that Hogwarts alternative, Xavier's School for Gifted Youngsters. Hanging on for the ride while Nightcrawler storms the White House (to the tempestuously prayerful, German-accented strains of ''Dies Irae'' from Mozart's ''Requiem''), we're on our own to recall that at the end of ''X-Men,'' a bigoted human constituency was pushing for a speciesist Anti-Mutant Registration Act. And that the mutants themselves were divided between those fighting for equal rights and the segregationists, who favored Mutant Power.
I, on the other hand, am delighted because director Bryan Singer has learned -- perhaps from the grace and warmth of Sam Raimi's ''Spider-Man''? -- that for all the fun things he can do with special effects and the siren call of Rebecca Romijn-Stamos' splendiferous figure as the shape-shifting Mystique, flashy showdowns matter little if they're not grounded in a witty appreciation of human vulnerability; our own weakness is what makes superhuman powers so alluring in the first place. ''X2'' revisits the rivalry between Professor Xavier and Magneto and their respective mutant congregations, and introduces some new recruits. (Among his many assets, Rogue's adoring classmate Iceman, played by Shawn Ashmore, can chill a soda bottle nicely.) But the real menace, fomenting unrest with all the sneakiness of a Tom Clancy Cold War-era bad guy, is the twisted human ex-Army commander Stryker (Brian Cox, who better?), who particularly enjoys tormenting Wolverine.
And for all the showpiece action sequences (the best of which involve Mystique's nifty chameleon work and Nightcrawler's delightful whooshes through walls trailing plumes of blue smoke), these superheroes are most appealing during their downtime. Jackman's hunky magnetism (have his claws gotten bigger, or is he just glad to see me?) is never so strong as when Wolverine is padding down the hallways of the X-Mansion, silently howling for Jean Grey. McKellen's Magneto is never so suavely perverse as when he's lolling in his cell like Hannibal Lecter's fellow prisoner-with-fine-diction. In moments of humor -- especially when Cumming is on the screen, his Nightcrawler a fabulous amalgam of devil, Boy Scout, ''Cabaret'' habitué, and Church Lady -- ''X2'' sparkles with a lightness of spirit that was missing from ''X-Men.''
And so, while I still find Big Showdown scenes more perfunctory than satisfying -- and there's a get-ready-for-''X3'' reel of them here, including an extended kung fu face-off between Wolverine and Stryker's mannequin-blank assistant, Deathstrike (Kelly Hu) -- there's invigorating charm in X2's many scenes of unhurried playfulness and gentle puns on serious themes of tolerance. ''Why not look like everyone else?'' Nightcrawler asks Mystique. ''Because we shouldn't have to,'' she replies, oblivious that most human men would leap tall buildings in a single bound if their women could look like her, blue scales and all.
Having mastered the big adventure picture and demonstrated his respect (required by fanboys) for the conventions of comic-book zaps and oofs, director Singer now also exhibits a welcome patience with the small adventures of human comedy. When junior member Iceman -- known to his Muggle-minded family as Bobby Drake -- brings a couple of the senior X-Men to his parents' Boston home, the concerned mother asks the son, who has turned out so different from the young man she thought he would be, ''Have you tried not being a mutant?'' Anyone who has ever revealed an anxiously held personal secret (Homosexual? Kosher? Republican?) knows that being a mutant isn't a choice, and that authenticity is the source of all superheroism, in comic books and in life.